Datapath Capture Card and two Graphic Cards

I'm new to the forum and if we go the Isadora way, will probably ask some more questions in the near future.

Since Isadora 2 has improved so much (great job!!!) we are thinking about using it on one of our stages.

For this I have to build custom PC's and I wonder if anyone has experience with Datapath Capture Cards (like this one: http://www.datapath.co.uk/products/video-capture-cards/vision-range/visionsd41s) and Isadora?

Will it be possible to get 4 streams of video (for example 3x Composite SD + 1x DVI HD) with this?

The other thing I am thinking about is using two graphics card to get more outputs.

A cheaper one for the Windows Desktop and one high end gamer card (for example GeForce GTX 970) for the Isadora output window.

@DusX is going to get back to you with further information. But I wrote an email to datapath to ask if they'd lend me one the card you mentioned above so that I can do some tests. We'll see what they have to say.

I use a this capture card: http://www.jigsaw24.com/pws/ProductDetails.ice?ProductID=12242

And i'm 99% sure the other card in that Mac Pro is a Nvidia Quadro 4800 (cant say 100% sorry different cards in different machines)

I get good performance from both cards.

Can capture 4 streams into the BM card but I use a range of BM convertors (analog to SDI / HDMI to SDI etc.) which can add a bit of latency (maybe 4-10 frames) its worst when doing and analog>digital conversion (not surprisingly).

I do not have experience with the Datapath product so I can't comment on this.

But your approach to building a PC with multiple video cards sounds correct.

With the newer Isadora Version 2 features the Geforce GPU will provide amazing performance.

If possible you may want to setup your PC with out optimus (http://www.nvidia.com/object/optimus_technology.html) since this technology has been a issue for Spout video sharing (http://spout.zeal.co/forums/topic/supported-video-cards-a-user-based-listing/).